Barrett's esophagus is a specialized intestinal metaplasia of normal squamous to columnar epithelium, which is thought to be a premalignant transformation and which is found in 80-100% of esophageal adenocarcinoma of the distal esophagus (1). The etiology of Barrett's esophagus is not well understood, but chronic gastroesophageal reflux is considered to be a major contributing factor (2). The presence of Barrett's esophagus increases the risk of developing adenocarcinoma 40 to 125-fold (3). The incidence of adenocarcinoma has increased 3.5-fold over the past 3 decades, which exceeds that of all other types of cancer (4, 5). Patients with adenocarcinomas of the esophagus present with advanced disease, and 5-year survival is approximately 25% (6). Currently, endoscopic surveillance is the only method of identifying patients with early-stage esophageal cancers arising in Barrett's esophagus.
Identification of biological markers of Barrett's esophagus progression may identify high risk patients for whom endoscopy would be indicated (8). Expressional profiling represents one method of identifying biological markers of Barrett's esophagus (9-12). However, no molecular markers that can be used to identify patients at higher risk for subsequent transformation of Barrett's esophagus to adenocarcinoma have been reported.
There exists a need in the art for new methods of evaluating the risk of progression of Barrett's esophagus to adenocarcinoma.